Rice Lake Lift Truck/Pallet Jack Scales - CLS-Series - Manual (Page 27)

Board Replacement 23
NOTES:
DC power wiring to the indicator should be 18 AWG to 14
AWG for DC+, DC-, and earth ground conductors.
The indicator will be connected directly to the battery of
the forklift. Ensure the type and style of forklift and the
type of power it provides will be compatible with the
indicator. Most propane, gas, and diesel fueled forklifts
provide 12 volts of power. Some diesel models also
provide 24 volts and electric forklifts provide 36 to 48
volts of power. The CLS-Series scales work best with
12-36 VDC power source.
In longer power cable runs, voltage drop over the power
conductor needs to be considered. See table and formula
below to compute voltage drop.
V
DROP
= (2.85A)(x
Ω / 1000ft)(length of run in ft.)
2.85A = maximum current draw from DC/DC power
supply
x
Ω = Ohms from Table 5-1
NOTE: DC voltage supplied to DC/DC power supply
should not be less than 9VDC. Using larger gauge
wire will result in less voltage drop.
Example:
100ft run with 18 AWG wire
V
DROP
= (2.85A)(6.385
Ω / 1000ft)(100 ft)
V
DROP
= 1.82V
12VDC will drop to 10.18V after 100ft run.
5.1.3 Serial Communications
Using on of the six-position connectors, provided in
the parts kit, wire the serial communications cables to
J4. Connector J3 provides connections for the
EDP/RS-232 port. Connect communications cables to
connectors J3 and J4 as shown in Table 2-3.
Once cables are attached, reconnect J3 and J4 to the
headers on the board (see Figure 5-2). Use cable ties
to secure serial cables to the inside of the enclosure.
T h e E D P p o r t s u p p o r t s f u l l d u p l e x R S - 2 3 2
communications only; the serial port provides either
active 20 mA output or duplex RS-232 transmission.
Both ports are configured using the SERIAL menu.
See Section 3.0 o n pag e 1 3 for configuration
information.
Table 5-2. J3 and J4 Pin Assignments
Digital inputs can be set to provide several indicator
functions, including all keypad functions. The inputs
are active (on) with low voltage (0 VDC) and can be
driven by TTL or 5V logic without additional
hardware. Use the DIG IN menu to configure the
digital inputs. LED’s on the CPU board light when
digital inputs are active.
Digital outputs are typically used to control relays that
drive other equipment. Outputs are designed to sink
not source, switching current. Each output is a
normally open connector circuit, capable of sinking
250 mA when active. Digital outputs are wired to
switch relays when the digital output is active (low, 0
VDC) with reference to 5 VDC supply. LEDs on the
CPU board light when the digital outputs are active.
Wire Gauge
(AWG)
Cable
Impedance
(OHMS/1000ft)
14 2.252
Ω
15 3.184
Ω
16 4.016
Ω
17 5.064
Ω
18 6.385
Ω
Table 5-1. Cable Impedance
Port Connector Pin Label
EDP/RS-232
(J-Box
connector) J3 1 TxD
2 RxD
3 Gnd
Serial Port J4 1 TxD
2 RxD
3 Gnd
4 20mA+
5 20mA–
6 Gnd
Port Connector Pin Label
Digital Input J2 1 DI 1
2 DI 2
3 Gnd
Digital
Output J6 1 Gnd
2 DO 1
3 DO 2
4 +5V
Table 5-3. J2 and J6 Pin Assignments